The present disclosure relates to a semiconductor memory device. More particularly, the present disclosure relates to an auto-refresh control apparatus.
In general, a DRAM periodically performs refresh in order to preserve cell data. Such a refresh increases current consumption as the integration degree of a DRAM increases.
Such a refresh is classified as auto-refresh for performing refresh by an external command and self-refresh for performing refresh by an internal command generated in a chip.
In the self-refresh, refresh can be optimally applied to a device by a refresh period. In the auto-refresh, refresh is performed without a special control scheme when an external auto-refresh command is generated.
The two types of refreshes are performed in order to preserve cell data. However, since the auto-refresh performs refresh by an external command, current consumption increases as compared with the self-refresh.